I. Field of the Invention
This invention relates to the correction of photocomposition film and specifically the correction of such film by manipulation of the correction area under ambient light conditions and the projection of the correction via an optical system employing a movable mirror.
II. Description of the Prior Art
A procedure known in the art of preparing final negative or positive films covers the area which is to be corrected on a layout with red shading. The red color covers every detail of the area to be changed; however, it is so sharply defined that the masking required for delineation from the neighboring characters by the segments of a correction film will at no point result in contact between the red color and the masking when projected. Furthermore, the red shading and masking allow for visual optical alignment but will be nontransparent to light on exposure. In the known correction procedure the delineation of a given location on the correction film, which replaces the red-shaded area in the original film, is determined by respectively cut conventional masking sheets. This requires that both the original film and the correction film be aligned with each other, after which the corrected portion of the latter is transferred by exposure onto the final film location. The area of the final film which receives the corrected portion of the correction film had previously remained unexposed because of the red shading on the original film. The advantage of the prior art is that, under full visual control, corrections can be made on positive film without requiring such time consuming methods as scraping, cutting, or gluing at the location to be corrected.